Coated abrasive article



Mardi 1, 1949- R. P. CARLTON COATED ABRASIVE ARTICLE originl Filed Jan. 2o, 1930,

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y orne 5 Patented Mar. l, 1949 COATED ABRASIVE ARTICLE Richard Paul carlton, st. Paul, Minn., asignar,

by mcsne assignments, to Be C poration, Troy, N. Y.

chusetts Application July 8, 1941, Serial No.

, 'a corporation ot Massa--y 401,484, now

Patent No. 2,376,342, dated May 22, 1945, which is a division of application Serial No. 422,065,

January 20, 1930, now Patent No. 2,318,570,

dated May 4, 1943. Divided and this application May 21, 1945, Serial No. 594,824

1 Claim. (Cl. 51-185) This invention relates in general to coated articles and to the art of coating, and more particularly to an improved method of and apparatus for applying puiverulent coatings to suitably adhesively coated surfaces, and while the invention finds particular utility in the art of making flexible abrasives, and is, therefore, described and illustrated for this purpose, it nds a wide eld of utility for analogous purposes.

This application is a division of my copending application Serial No. 401,484, filed July 8, 1941, now Patent No. 2,376,342, granted May 22, 1945, as a division of my application Serial Number 422,065, led January 20, 1930, now Patent No. 2,318,570, granted May 4, 1943.

It is well known that in the art of making sandpaper, emery paper or cloth and similar abrasive articles, a iiexible or in some cases, a rigid, backing of paper, cloth, wood or the like is employed, to which is applied a coating of an adhesive substance, such as animal or vegetable glue, or where a waterproof article is desired, the backing may be coated with any of the now well known waterproof adhesives for this purpose, and while the coating is still wet or unset, a suitable abrasive material such as garnet, corundum, sand or the like is applied thereto. The grains of abrasive substances are usually applied by gravity upon the upper adhesive coated surface of the backing, and they lie in the adhesive material in haphazard fashion due to the elongated nature of the abrasive particles, and in a large degree, the facets or cutting edges of the individual grains or grits often lie nat upon or are embedded in the adhesive coating in such a manner that in some instances their best cutting edges never come into contact with the work or at best are brought ineiciently into contact therewith. The invention here has as one of its objects to measurably increase the number of grits whose longer or greater dimensions are perpendicular to the surface of the backing, thereby to present more emciently the cutting edges to the work, and increase the cutting ability and life of the abrasive article.

The principal objects and advantages of this invention reside in the provision of an improved abrasive coated article, such, for example, as sandpaper, emery cloth, or the like, wherein the abrasive grits or grains lie in position on the backing for increasing the cutting e'ect and durability of the abrasive article; the provision of an improved abrasive article wherein the abrasive grits are disposed so that their cutting facets are presented in position to more efficiently engage the work and thereby produce a, sharper article; and the provision of an improved abrasive article wherein the abrasive grains or grits are applied thereto with dimension substantially perpendicular to the plane of the backing.

This invention further includes as objects and advantages thereof, the provision of an improved method of and apparatus for manufacturing abrasive articles; and the provision of an improved method of and apparatus for causing the articles of pulverulent material to impinge upon and assume a position in the adhesive coated surface substantially normal or perpendicular to the surface of the backing.

The foregoing and such other objects and advantages as may appear 'or be pointed out as this description proceeds are attained in the structure illustrated in the accompanying drawing.

The method of the present invention includes as steps thereof the feeding of a web or strip of paper or other fabric at a predetermined rate of speed, applying an adhesive substance to the under side of the sheet, or applying the adhesive coating to one side and then moving the sheet with the coated side out, and simultaneously with the movement of the coated sheet, causing a grit or abrasive material to be applied to this side.

In my originalI application Serial No. 422,065, filed January 20, 1930, and in my copending application Serial No. 401,484, filed July 8, 1941, as a division of said original application Serial No. 422,065, I disclosed in the specifications and drawings thereof various different forms of apparatus and methods for depositing the abrasive grains in the adhesive coating on the backing with their major axes substantially perpendicular to the surface of the backing. These disclosures included various means of propelling the abrasive particles through an intervening space by mechanical or electrical force as well as the apparatus and method here disclosed for causing the abrasive particles to assume an erect position on a carrier surface and then bringing the particles while so positioned into embedding contact with the adhesive coating on the backing sheet. This latter method not only effects the desired positioning of the abrasive grains substantially perpendicular to the backing but also results in the positioning of the particles with their outer ends in a surface determined by the surface of the carrier surface from which they are transferred to the adhesive coating of the their longer or greater indicated at |01, the lower one of said pair be ing in contact with adhesive material contained in a tray or tank |05 whereby an adhesive coating is applied to one side of the moving web.

The moving web thus ladhesively coatedis carried over a roller |08, thence over a roller |09, said roller |09 being mounted on a shaft carried in a bearing arm or arms I I pivotally mounted at III, whereby the roller |09 may be raised and lowered in the substantially vertical plane of the arrows I I2, thus permitting the lower flight H3 of the paper web to be elevated or depressed, as the case may be.

Mineral is deposited from a hopper ||4 onto a conveyor ||5 trained over rollers IIB and lla, the upper ight of said conveyor passing beneath the roller |09 and the moving web and conveying mineral, that is, the grit, to a point adjacent to the roller |09. j

Preferably immediately below the axis of the roller |09 and below the upper flight ||'l of the conveyor IIS, I provide an electro-magnet |I0 which is so mounted that its magnetic ux passes through the conveyor and causes the mineral particles to stand erect, as indicated at I |9,as they move along with the upper flight of the conveyor. While the mineral particles are thus standing erect they come into contact with the adhesively coated side of the paper backing and are thus picked upby it and conveyed away, the backing being trained over rollers and carried to festoons for drying. It will be observed that the angularity of the lower stretch IIB of the paper web is such that it lies upwardly to the conveyor ||5. In this way the particles of grit adhering to the paper are not knocked down by other particles remainingon the conveyor, it being understood that the grit is fed somewhat in excess of the required amount so that an adequate amount will be deposited on the adhesively coated side oi the backing. The excess mineral drops off the conveyor ||1 and is carried to a collecting means by a conveyor |2I. It may be desirable that a certain amount oi pressure be exerted on the erect particles oi mineral so as to cause them to impinge upon the adhesively coated side oi the paper.

By manipulation otthe arms IIO, an adjustment of the pressure of the roller |00 may be attained.

It will be understood that by varying the amount ot mineral i'ed from the hopper, the

strength of the electro-magnet, that is, the

strength of the ow current transferred, and the position oi adjustment oi' the roller |00 the assembly may all be properly correlated for obtaining the desired grade. oi finished article. Since the abrasive particles are supportedupon the surface of the conveyor belt any variation in the longer dimensions of the particles will affect the depth to which they become embedded in the adhesive coating but the relative position oi the ends resting on the conveyor belt will be determined by the surface of the belt which is ordinarily a smooth plane.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

An abrasive sheet material comprising a back-- ing and a layer of abrasive. particles oi.' various sizes and shapes bonded thereto by an adhesive binder coat,all of said abrasive particles having their major axes parallel and perpendicular to the plane of the backing and'having their exposed ends lying in a common plane parallel to the-plane of the backing.

RICHARD PAUL CARLTON,

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date Re. 22,419 Smyser -j Jan. 11, 1944 922,382 Brenizer May 18, 1909 945,931 Gardner Jan. 11, 1910 1,788,600 Smyser Jan. 13, 1931 1,854,071 Schacht Apr. 12, 1932 2,033,991 Melton et al Mar. 17, 1936 2,184,348 Kirchner et al Dec. 26, 1939 2,184,896 Oglesby Dec. 26, 1939 2,255,294 Melton et al Sept. 9, 1941 

